Triple point of Yukawa systems

The molecular dynamics simulations of Yukawa (i.e., screened-Coulomb) systems that were applied to the regime of weak screening in an earlier study [S. Hamaguchi, R. T. Farouki, and D. H. E. Dubin, J. Chem. Phys. 105, 7641 (1996)] are extended to the strong screening regime. Transition temperatures at the fluid-solid phase boundary and the solid-solid phase boundary are obtained as functions of the screening parameter kappa = a/lambda(D) (i.e., the ratio of the Wigner-Seitz radius a to the Debye length lambda(D)). The resulting phase diagram also covers the triple point-the intersection of the fluid-solid and solid-solid phase boundaries-at kappa = 4.28 and Gamma = 5.6 x 10(3), where Gamma is the ratio of the Coulomb potential energy to the kinetic energy per particle (i.e., Gamma = Q(2)/4 pi epsilon(0)akT, where Q is the charge of each Yukawa particle and T is the system temperature). Yukawa systems serve as models for plasmas and colloidal suspensions of charged particulates.